Opel denies reports of emissions cheating

German automaker Opel, a unit of US giant General Motors, rejected on Tuesday a media report which accused it of manipulating the software of the engine of one of its diesel models.

"Opel clearly rejects the allegations. It is not true that Opel dealers installed a modified software into the 1.6-litre diesel engine of the Zafira Tourer which changes the emissions behaviour of the vehicle," the company said in a statement.

On Monday, the Belgian broadcaster VRT had reported on its website that Opel had been secretly modifying the emissions performance of its cars using unexplained software updates since the Volkswagen pollution-cheating scandal erupted in September.

Global carmakers are currently under scrutiny following the revelation last September that VW installed so-called defeat devices in 11 milllion diesel vehicles worldwide aimed at cheating emissions regulations.

French rival Renault said Tuesday it was recalling thousands of vehicles to make engine tweaks as the French carmaker grapples with emission levels found to exceed anti-pollution norms in some of its cars.

According to VRT, the level of the Opel cars' emission of nitrogen oxides was originally much higher than EU limits. But following a software update carried out by a local dealership alongside a routine service, the cars' emissions performance improved, the broadcaster claimed.

The service update carried out on the Zafira Tourer model "had nothing to do with a change in the emissions values," Opel insisted, without specifying what the update was for.